Recently, one of my friends passed away, leaving behind two children, one aged 5 and the other just

Recently, one of my friends passed away, leaving behind two children, one aged 5 and the other just 6 months old. His wife received approximately one crore from the insurance company and his workplace. However, there is now a dispute as the deceased mother-in-law is trying to gain control of the funds. She convinced her daughter to marry someone else and take custody of the children, but in reality, she wants to control the funds for her own benefit. The grandparents want the money to be deposited into the children's accounts and notified if any withdrawals are made. They do not want anyone to be able to withdraw the funds without their knowledge. They also wish to obtain custody of the children due to concerns about their education and quality of life. Is it possible for the grandparents to gain custody of the children and hold the funds in a bank account until the children are of legal age to access them.